Laminated cards are widely used as certificates of citizenship, employee identification cards, passports, driver's licenses, transaction cards, and other applications of a similar nature in which such cards establish a person's authorization to conduct certain activities. Laminated cards typically comprise a card-shaped substrate made from a suitable material such as paper, cardboard, or plastic. Information such as photographs, data, textual information, graphics, or the like, may be printed on one or both sides of the cards. In some applications, information may also be optically or magnetically stored on recording media provided within or on the surfaces of such cards.
In view of the widespread use of laminated cards, it is important that the information provided with the cards be protected against damage. It is also important that the information be protected against unauthorized alterations. Accordingly, the information provided on the substrate may be covered by a protective plastic laminate sheet which is bonded to the substrate. Most commonly, heat-activated adhesives are used to accomplish such bonding.
When printed information on the substrate is protected by a plastic laminate sheet, the plastic sheet would have to be removed from the substrate in order to alter the printed information and then subsequently replaced after the alteration has been completed. To protect against this activity, the plastic sheet may include an authentication image of a type which is destroyed when the plastic film is removed, such as a holographic image, ultraviolet image, an image formed with pearlescent ink, a chemical patch, and the like. In an alternative approach, the authentication image is substantially invisible until the plastic is removed, after which the image becomes permanently visible. In either approach, the change in the state of the image indicates that the plastic film has been removed from the substrate. This, in turn, suggests that the printed information on the substrate may have been altered.
A number of different approaches have been used to laminate heat bondable plastic laminate sheets to card substrates, but such approaches which have been used for manufacturing large quantities of laminated cards tend to generate a substantial amount of waste material. For example, according to a "decal" approach, a 2 to 3 micron thick, heat transferrable, plastic laminate material is supported upon a carrier web. To apply the laminate material to the substrate, the substrate and the laminate material are brought into contact, and then the laminate material is transferred to the card using heat. This approach does not work too well, because the 2 to 3 micron thick coating is too thin to adequately protect the card against scratches and ultraviolet bleaching. Additionally, the left-over carrier web becomes scrap which must be thrown away. Additionally, left-over, and hence wasted, laminate material remains on the carrier web in between the transferred areas.
According to a "die-cut" approach, a much thicker laminate material is supported upon a carrier web. with the laminate material being supported upon the carrier web, a plurality of individual, spaced-apart laminate sheets are die-cut in the laminate material in a manner such that the carrier web itself is not cut at all, or at least is not cut entirely through. After die-cutting, the excess laminate material between the spaced-apart sheets is removed from the web and thrown away as scrap, thus leaving only the spaced apart, die cut sheets on the web. The individual sheets must be spaced apart relative to each other when using this approach in order to allow registration marks to be placed on the material in the unused regions between the sheets. The registration marks are used to register the sheets on corresponding substrates. Each successive die-cut sheet is then bonded to a corresponding substrate using a heater. The individual sheets must also be spaced apart in order to allow the carrier web to be pulled away from the heater after bonding in order to bring the next sheet into position for bonding to the next substrate. Like the process described above with respect to the 2 to 3 micron thick laminate material, the left-over carrier web from this approach also becomes scrap which must be thrown away.
An approach is needed which allows high volumes of laminated substrates to be fabricated without generating so much waste.